Piezoelectric Actuator Resonance Control via Dynamic Inductance
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Acoustic telemetry systems in the oil and gas industry face inefficiencies due to changes in temperature and pressure affecting the resonance of piezoelectric actuators in drillstrings, leading to excessive current consumption or reduced wave energy output, exacerbated by dynamic mechanical loading and noise from drilling operations.
Innovation Solution
A closed-loop control system dynamically adjusts the inductance of the transformer by switching taps to maintain resonance, compensating for capacitance changes caused by temperature and pressure variations, ensuring efficient operation of the piezoelectric actuator by maintaining a resonant circuit state.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If the piezoelectric actuator operates in a resonant circuit, then the efficiency of acoustic telemetry is improved, but the resonance condition is disrupted by temperature and pressure changes causing capacitance variations
Solution Approach 1:
A feedback control system is implemented that continuously monitors the operating conditions (temperature and pressure) and dynamically adjusts the inductance value to maintain resonance. The controller receives signals from sensors detecting capacitance changes and modifies the inductance accordingly, ensuring the circuit remains at optimal resonance despite environmental variations.
Solution Approach 2:
The inductance value is made variable rather than fixed, allowing it to be adjusted in response to changing conditions. By changing the inductance parameter dynamically, the system compensates for capacitance variations caused by temperature and pressure changes, maintaining the resonant frequency and optimal efficiency.
2Reliability
If the capacitance of the piezoelectric actuator changes due to temperature and pressure, then the resonance frequency shifts, but increasing inductance adjustment complexity
Solution Approach 1:
The feedback control system automatically monitors resonance conditions and adjusts inductance without requiring complex manual intervention. Sensors detect changes in capacitance or resonance frequency, and the controller automatically modifies the inductance value, simplifying the overall system architecture despite the dynamic adjustment capability.
Solution Approach 2:
The system is designed to self-regulate by automatically detecting resonance deviations and correcting them through inductance adjustment. The control mechanism monitors its own performance and makes necessary adjustments without external intervention, reducing the need for complex external control systems.
3Power
If the piezoelectric actuator is subjected to dynamic mechanical loading, then the wave energy output varies, but maintaining constant resonance becomes difficult
Solution Approach 1:
The inductance value is made dynamically adjustable to match the changing mechanical loading conditions. As the mechanical load varies, the system continuously adapts the inductance to maintain resonance, allowing the wave energy output to remain optimized despite varying operating conditions such as depth and drilling dynamics.
Solution Approach 2:
The electrical parameters (inductance) are changed in response to mechanical parameter changes (loading). This coordination between mechanical and electrical parameter adjustments ensures that the piezoelectric actuator maintains optimal resonance and wave energy output throughout varying drilling operations.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This solution enhances the efficiency of acoustic telemetry by maintaining optimal resonance, reducing power consumption and signal distortion, and improving the reliability of data transmission through drillstrings despite varying drilling conditions.
Implementation Method 1
a transducer comprising a stack of piezoelectric discs (the 'stack'), arranged physically in series, that are constrained between two metal shoulders disposed on a mandrel... the stack being energised by the application of a high voltage. As this high voltage is applied it causes the stack to either increase or decrease its axial length, and this is transferred to the mandrel and cover. Elastic deformation of the mandrel and cover due to periodic changes in the applied voltage causes extensional waves to propagate away from the two faces of the stack.
Implementation Method 2
A simple way to apply a periodic high voltage to a stack is to utilize a transformer whose secondary winding is connected to the stack, and whose primary winding is attached to a switching unit and a power source... In order that the transmitter system is run efficiently it is helpful to make the practical transformer/stack combination (i.e. tank circuit) resonant with a resonance quality factor (Q) of the order 4 to 10.
Implementation Method 3
In order that the transmitter system is run efficiently it is helpful to make the practical transformer/stack combination (i.e. tank circuit) resonant with a resonance quality factor (Q) of the order 4 to 10. It will be evident that the most efficient utilization of such a resonant circuit is to operate in the centre of its resonance band, implying that the stack's capacitance and the transformer's inductance is matched at the resonant frequency.
Data Source
AI summary
This invention applies to the means whereby capacitance changes due to varying temperature and/or pressure in a piezoelectric transducer used for acoustic telemetry in a drilling environment is dynamically offset by modifying one or more parameters associated with the drive or control circuitry of said transducer. The object of the invention is to closely maintain the transducer in a resonant mode, thereby ensuring optimum energy consumption.